If you can ride a two-wheeler, you're qualified to hit the timber and rock "trails" at Ray's Indoor Mountain Bike Park in Milwaukee. But don't be fooled: Ray's isn't your average family entertainment venue.

Located inside a shuttered 110,000-square-foot Menard's home-improvement store, Ray's does not feature inflatable slides, kid-friendly padded walls, video games or ball pits. Instead, as the company stresses, the indoor mountain bike playground is built of wood, nails and concrete, and it involves some risk. And that's exactly why this plywood-scented bike park is so much fun.

Though I haven't yet hit the outdoor mountain bike trails, I showed up at Ray's on a recent weekend with three other newbies: My two boys, ages 7 and 5, and my 14-year-old niece. The park is designed primarily for adult mountain biking (and, secondarily, BMX) enthusiasts, but there's plenty for adventurous children. Just make sure that they aren't on training wheels or striders and that those younger than 8 are accompanied by an adult at all times.

The original Ray's, which opened in Cleveland in 2004, targeted the aggressive mountain bike rider; the unique concept gained so much momentum among snowbound Midwestern trail riders that owner Ray Petro opened a second location, in Milwaukee, in 2010. Each summer, the parks close for remodeling and upgrades. When Ray's in Milwaukee reopened last fall, it sported a vastly improved novice section to accommodate increased demand from beginners.

After checking in — signing serious-sounding waivers, renting single-speed bikes, knee and elbow pads and donning our required helmets — we hit the easiest path in the building: the yellow floor level XC loop, suitable for anyone who can ride on a sidewalk. The yellow trail led us to the new beginner section: a quiet and secluded room that allows first-timers to practice riding on treacherous wooden planks, rocks, logs, curved banks (berms) and small mounds (rollers) without having to share the trails with more experienced riders.

Eventually my 7-year-old wanted more; he pedaled up a ramp to the green XC trail on the second floor. This trail had such steep roller-coasterlike descents that he initially walked his bike down the more terrifying stretches. He also bypassed the more difficult spurs. Soon, though, he mustered his courage (meaning I had to as well) and could ride the entire third-of-a-mile loop.

Back at the beginners sport section, my teen niece tried her hand at riding over obstacles — logs, rocks, two-by-fours and teeter-totters. The 5-year-old wanted to go home, but the 7-year-old made a friend, and together the two young boys tried the new micro-rhythm track. This introduction to a "jump line" featured an out and back course of rollers, boxes and beginner jumps and turned out to be my son's favorite part of the park. "It feels like you're flying!" he said. Eventually he took a break — but only because he "hurt his tentacles." Ahem.

Lunch is "bring your own" (vending machine snacks and drinks are available), though people often have food delivered, and we ate at one of the many picnic tables in the lounge area near the fireplace on the main level. Then we wandered to the expert areas, where we watched the expert riders fly through the air, executing daring flips and 180s and practicing "no handers," landing on their bikes or in foam pits.

This is what most people assume Ray's is like, especially if they've watched YouTube videos, said Milwaukee manager Eric Schutt, who also does Ray's marketing. No one bothers taking pictures of older people riding on the less dramatic yellow trail, he said. "We benefit from the viral, customer-based content, but it also creates a visually aggressive image," Schutt said.

In reality, Ray's offers something for every level and age. And though mountain bikers and BMXers pedal in different circles, Schutt said, there is no culture clash. Mean looks, growling and "throwing the malarkey" are all no-nos at Ray's. (Mustaches are allowed but not encouraged.) And once when the 7-year-old crashed and I was busy chatting on my cellphone and not paying attention, someone quickly came and alerted me.

Still, the kids lasted less than two hours on the first day. Instead of driving back to Chicago, we checked in at the immaculate Four Points by Sheraton, which offers a discounted rate of $74 if you bike at Ray's. We went swimming; an hour later, the 7-year old was begging to go back to Ray's.

My own trip led ultimately to the pump track, an endless loop of rolling bumps and banked corners. Ideally you ride without pedaling, using your body weight and the small inclines to propel you forward. I was eager to try what many people called the best workout in the park, but I quickly learned that slowing down (chickening out) when you get to the berms is a sure way to topple over.

As with every part of the park, confidence and momentum are keys to staying upright. After a series of graceless wipeouts, my cocky 7-year-old offered some advice. "Just go, mom!" he said.

I went. With my heart in my throat. And the thrill of finally getting it is why we'll head back to Ray's.

General admission on weekdays is $19.99, including helmet, elbow pads and shinguards. Weekends are $25.99. Multiday and children's discounts are available.

Mountain or BMX bike rentals: Same-day walk-in, $13.99. Prepaid reserved, $18.99. (Reservations recommended on weekends.) You can take in your own bike, but hybrid, cyclocross and road bikes are not allowed.

Helmets and working brakes are required. Gloves, elbow pads, shinguards, long-sleeve shirts and long pants are recommended. Gloves, helmets and other protective gear can be purchased at the park.

GoPro HD wearable (on the helmet) video cameras: $30 for the day. Rental includes a 2GB memory card to keep.

Hours: Noon-10 p.m. Monday-Friday; 9 a.m.-10 p.m. Saturday-Sunday.

Ray's offers two discounted hotel deals, including riding packages. See the website for details.

Riders younger than 16 must be accompanied by an adult; that adult has to stay in the park during the entire visit. Riders younger than 8 must have an adult riding with them. Ray's will close April 29 for the summer reconstruction season and reopen in October.